1. Field of the Invention
The present invention relates to a semiconductor device used, e.g., for high power switching.
2. Background Art
Japanese Laid-Open Patent Publication No. 2009-076703 discloses a semiconductor device having a surface electrode of aluminum formed on the surface of its semiconductor substrate. A metal film is formed on the surface electrode. Wires are soldered to the metal film.
Since the adhesion between the surface electrode and the metal film is high, when the semiconductor device is subjected to thermal stress, stress concentration occurs at the ends of the metal film. The stress at the ends of the metal film may damage the portions of the surface electrode immediately underlying these ends. If the surface electrode is damaged, it is not possible to ensure sufficient reliability of the semiconductor device.